extension cord

Hilldweller

Super Active Member
Mar 2, 2021
1,113
Hog Waller, GA

popup-flyer

Active Member
May 11, 2021
350
Central Texas
A/c and lights

Your A/C will likely require far more power than your 15amp circuit can provide. I walked away from a purchase of an RV because I told the person over the phone I expected to see everything operational so he plugged it in with a 15amp wall adapter.

When I arrived he kept trying to get the A/C to come on and it moaned and groaned but wouldn't come on. No telling how many times he had done that in the past. It can damage the A/C to underpower it.

For that reason I put a 30amp RV plug in my breaker panel (that is in the garage) and an outlet on the wall.

That 15amp house plug is for you to run the power outlets and/or the onboard Inverter. but not rated for the campers maximum capacity.
 

Sjm9911

Super Active Member
May 31, 2018
12,566
Nj
An ac will run , but that will be about it. You might get ac and lights on a dedicated 15 amp outlet with leds. So that means nothing else in the house on it. Better would be a 20 amp deticated outlet, but once again ac and lights or no ac and fridge. They asked about the distance, because that will determan the guage of the cord.
 

popup-flyer

Active Member
May 11, 2021
350
Central Texas
An ac will run , but that will be about it. You might get ac and lights on a dedicated 15 amp outlet with leds. So that means nothing else in the house on it. Better would be a 20 amp deticated outlet, but once again ac and lights or no ac and fridge. They asked about the distance, because that will determan the guage of the cord.

I popped the cover off my A/C and read the label on it. 15AMP to Run, but up to 20 to Start. Just because you can get it to come on and things spin doesn't mean your not doing harm and all is well.
 

Sjm9911

Super Active Member
May 31, 2018
12,566
Nj
I popped the cover off my A/C and read the label on it. 15AMP to Run, but up to 20 to Start. Just because you can get it to come on and things spin doesn't mean your not doing harm and all is well.
Depends on the draw size and age of the unit. Most will run fine , if your just running one. As i said 20 amp outlet is better. I wouldn't run anything else but the ac on a 15 amp. You are corect, a underpowered ac can cause the compresser to get damaged.
 

Snow

Super Active Member
Jul 19, 2007
12,274
Generally you should nit run the ac on a 15amp source for the reasons noted above.. You can however install a soft start setup that will lower the initial start up amps needed. Think most new (as in last 2-3 years) have these to begin with..

When I plug in at home it is to run the fridge and charge the battery.. I use a heavy duty extension cord. When camping I carry 100ft of 30amp cord and have used all of it plus the 30ft on the trailer many times..
 

bupkis

Howdy!
Mar 3, 2006
7,960
N. TX
Many a 15A outlet is protected by a 20A breaker and 12g wire (not all).
Find out! Turn off any thing that may be on that circuit to use a a/c.
25' 12/3 extension cord or a 30A RV ext cord.
 

davido

Super Active Member
Jul 17, 2014
1,424
Ideally you would have an outlet adjacent to your trailer that supplies the same sort of Shore Power as what the RV wants as input. Typically modern popups use 30A at 110-115VAC. So you would want a 30A plug, supplied by a 30A circuit.

If you cannot have a 30A outlet, then you would probably be plugging into a 15A circuit. In that case, you want the shortest run of 15A extension cord possible, at the highest gauge available. And you want the best 15A/30A adapter available, and you want to transition to the 30A cordset as close to the adapter as possible. A long 14awg extension cord between the wall and the adapter is not going to supply as strong a current as a short 10AWG cord, for example. And it's better to run more 30A cordset, less 15A extension cord.

Even so, let's say you get a full 15A available at the trailer's input. That means you're going to struggle to run a rooftop RV air conditioner. But you've got plenty of power for charging the battery, running power tools, a space heater, trailer loads (lights, water pump). Just not enough for the AC.

You may get lucky and find that you're able to run the AC too. Just don't count on it unless you have a 30A hookup.
 

popup-flyer

Active Member
May 11, 2021
350
Central Texas
There is a lot of well... really risky advice on this thread. The reason I wrote what I did about the plug/circuit type being the proper plug with 30amp outlet/breaker behind is because we don't know what the OP has as far as A/C or extension cord. We also don't know their knowledge/experience with power circuits or A/C units. You can't just assume what works for you will work for everyone.

Assume nothing!
I have a 16 YO house and every 15amp outlet has a 20amp breaker behind it.
Pretty much every wall outlet in a residential home is rated for 15 amps as a general rule of thumb. Even if the breaker is rated 20 amps is the wire to the outlet? Is the outlet 15amps? Pulling too much amperage through an incorrectly sized wire/outlet can start a fire pure and simple. If it were rated for 20 it would be a 20amp outlet with a different plug style (one vertical/horizontal side) such as in a garage freezer style plug OR its a 220 outlet designed for your clothes dryer or air conditioner or stove/oven.

20 amp plugs:
https://www.homedepot.com/b/Electri...s/20-amp/N-5yc1vZc33aZ1z17m1v?storeSelection=

OP:
Please be sure and read the maximum amperage draw of your A/C unit which will likely entail removing the cover to find the label to be absolutely sure or at least knowing your make/model info of your A/C unit and looking it up based on that. After you know that make sure the outlet and circuit breaker are rated for at least that much before turning on the A/C. I will say it again, just because it comes on... runs and even cools does not mean you are not doing damage.

Consider the old axiom.... "Free advice is worth every penny you paid for it!"
 
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Sjm9911

Super Active Member
May 31, 2018
12,566
Nj
If your unsure , look for a garage door opener outlet. Check those as there supost to be deticated 20 amp outlets. Then plug the ac into that one directly ( just dont use the garage door too). 20 amp outlets look diffrent from 15 amp ones.
 

popup-flyer

Active Member
May 11, 2021
350
Central Texas
I had to correct my post above because I wrote 15amp breakers in my home when I meant 20 amps.

So I have 20 amp breakers, 20 amp rated wire but 15 amp plugs as per this photo I just took with an outlet cover off. I even have some much nicer outlets that I changed out that are smart outlets and even decorative "rectangle" style that are all the same as this one, 15 amps:

20210730_164656.jpg

Will my AC run off this? You bet it will. Might I damage the A/C? Depends on its current draw/needs. Will I be doing damage to my outlet by overdriving it? Most certainly. I will weaken the components making their rating even lower and it will get hot because I am pulling too much power. The longer I do it the worse it will be for it.

If you want to use a 20 amp extension cord it will be at least 12 gauge wire per strand inside and have the sideways plug for a 20amp outlet.

I know everyone is just trying to help but I don't want the OP to find out the hard way that just because it hooks up doesnt mean you should do it.
 
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Sjm9911

Super Active Member
May 31, 2018
12,566
Nj
I had to correct my post above because I wrote 15amp breakers in my home when I meant 20 amps.

So I have 20 amp breakers, 20 amp rated wire but 15 amp plugs as per this photo I just took with an outlet cover off. I even have some much nicer outlets that I changed out that are smart outlets and even decorative "rectangle" style that are all the same as this one, 15 amps:

View attachment 77403

Will my AC run off this? You bet it will. Might I damage the A/C? Depends on its current draw/needs. Will I be doing damage to my outlet by overdriving it? Most certainly. I will weaken the components making their rating even lower and it will get hot because I am pulling too much power. The longer I do it the worse it will be for it.

If you want to use a 20 amp extension cord it will be at least 12 gauge wire per strand inside and have the sideways plug for a 20amp outlet.

I know everyone is just trying to help but I don't want the OP to find out the hard way that just because it hooks up doesnt mean you should do it.
I had some long stuff typed out, but your right. If you dont know and have to ask , then a 20 amp outlet with appropriate extension cord ( 12/2 ) or better is probably the only way to run the ac and only the ac. There are exceptions, and if you are not comfortable or dont know them then dont use anything but the aformentioned. Ok see i agreed. I'm stubborn and don't do that often.
 

bupkis

Howdy!
Mar 3, 2006
7,960
N. TX
Camp ground voltage will likely be low when lots of folks are running their a/c. You won't even know you are operating your a/c at low voltage cuz some one on a forum said you are good to go cuz you are using a 30A plug, what a crock! Let's not even consider as temps rise all the RV a/c are using more power dropping the voltage more and more.

The OP may be gone so lets show pics of our 1954 home with 7 or 9 20A breakers
no 240v, 60A service.
ac.jpg
 
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